216 research outputs found
Novel insights into Staphylococcus aureus deep bone infections: the involvement of osteocytes
No full textPeriprosthetic joint infection (PJI) is a potentially devastating complication of orthopedic joint replacement surgery. PJI with associated osteomyelitis is particularly problematic and difficult to cure. Whether viable osteocytes, the predominant cell type in mineralized bone tissue, have a role in these infections is not clear, although their involvement might contribute to the difficulty in detecting and clearing PJI. Here, using Staphylococcus aureus, the most common pathogen in PJI, we demonstrate intracellular infection of human-osteocyte-like cells in vitro and S. aureus adaptation by forming quasi-dormant small-colony variants (SCVs). Consistent patterns of host gene expression were observed between in vitro-infected osteocyte-like cultures, an ex vivo human bone infection model, and bone samples obtained from PJI patients. Finally, we confirm S. aureus infection of osteocytes in clinical cases of PJI. Our findings are consistent with osteocyte infection being a feature of human PJI and suggest that this cell type may provide a reservoir for silent or persistent infection. We suggest that elucidating the molecular/cellular mechanism(s) of osteocyte-bacterium interactions will contribute to better understanding of PJI and osteomyelitis, improved pathogen detection, and treatment.IMPORTANCE Periprosthetic joint infections (PJIs) are increasing and are recognized as one of the most common modes of failure of joint replacements. Osteomyelitis arising from PJI is challenging to treat and difficult to cure and increases patient mortality 5-fold. Staphylococcus aureus is the most common pathogen causing PJI. PJI can have subtle symptoms and lie dormant or go undiagnosed for many years, suggesting persistent bacterial infection. Osteocytes, the major bone cell type, reside in bony caves and tunnels, the lacuno-canalicular system. We report here that S. aureus can infect and reside in human osteocytes without causing cell death both experimentally and in bone samples from patients with PJI. We demonstrate that osteocytes respond to infection by the differential regulation of a large number of genes. S. aureus adapts during intracellular infection of osteocytes by adopting the quasi-dormant small-colony variant (SCV) lifestyle, which might contribute to persistent or silent infection. Our findings shed new light on the etiology of PJI and osteomyelitis in general.Dongqing Yang, Asiri R. Wijenayaka, Lucian B. Solomon, Stephen M. Pederson, David M. Findlay, Stephen P. Kidd, Gerald J. Atkins, Mark S. Smeltzer, Richard P. Novic
Review of \u3ci\u3eThe Holocaust in American Life\u3c/i\u3e, by Peter Novick.
No full textThe Holocaust has undeniably become a fixture in American culture. What has come to be called the Americanization of the Holocaust is the subject of several recent books, a lively discussion within the American Jewish community, and even a course in American history at the University of Heidelberg. Among the many attempts to document and explain how the Holocaust has been Americanized, perhaps the most ambitious and provocative is Peter Novick\u27s The Holocaust in American Life. The book is ambitious both on account of its chronological breadth, covering the entire period from the Second World War to the present day, as well as on account of the wide range of published and unpublished sources consulted by the author. It is provocative primarily because it argues that the preoccupation with the Holocaust has not been a healthy phenomenon for American society, its Jewish minority, and a balanced understanding of the Holocaust itself
Streptococcus pneumoniae Capsular Polysaccharide
No full textPublished: 12 April 2019The polysaccharide capsule of Streptococcus pneumoniae is the dominant surface structure of the organism and plays a critical role in virulence, principally by interfering with host opsonophagocytic clearance mechanisms. The capsule is the target of current pneumococcal vaccines, but there are 98 currently recognised polysaccharide serotypes and protection is strictly serotype-specific. Widespread use of these vaccines is driving changes in serotype prevalence in both carriage and disease. This chapter summarises current knowledge on the role of the capsule and its regulation in pathogenesis, the mechanisms of capsule synthesis, the genetic basis for serotype differences, and provides insights into how so many structurally distinct capsular serotypes have evolved. Such knowledge will inform ongoing refinement of pneumococcal vaccination strategies.James C. Paton and Claudia Trappett
ASU West Construction Begins with the Inauguration of a Tradition
No full textabstract: This press release discusses the ASU West Symbolic Bell that was rung at the groundbreaking.The bell was a gift of Mrs. Betty Bool and the Arizona Historical Society and is a permanent fixture on the West campus
ASU West Launches Faculty Recruiting Campaign
No full textabstract: Draft of a news release with handwritten editing
Dutiful Justice (book review)
No full textSheldon Novick’s biography, Honorable Justice: The Life of Oliver Wendell Holmes, is a traditional biography of one of the most important public figures in the United States since the Civil War.
Although the author disclaims it, Honorable Justice is a defense of Holmes. Novick writes of some of Holmes’ faults, but too often Holmes’ human imperfections are defended as strengths. It appears that Novick was trying hard to defend Holmes from late twentieth century critiques. This defense of Holmes seems a misguided attempt to re(de)ify Holmes to a group of readers which will likely include a large proportion of skeptical, professional ironists.
Holmes was a complex man whose life is worth the effort Novick clearly expended on the biography. The complexity of Holmes is pursued on enough occasions that the book is worthwhile reading, and for that Novick should be commended. However, it remains uncertain whether Holmes was an honorable man, or an Honorable Justice
ACKNOWLEDGMENTS The author would like to convey his appreciation to his supervisory committee
No full textArroyo) for their support and guidance. Special thanks go to Dr. Crane who gave the author the opportunity to work on the autonomous vehicle project and continually provided important insight and advice. This work would not have been possible without the support of the Air Force Research Laboratory at Tyndall Air Force Base, Florida. Thanks go to Al Neese and the rest of his staff. The author’s work presented in this dissertation focuses on only part of the tasks required for autonomous navigation. Other project members have addressed the remaining tasks. Therefore, thanks go to those who have worked on the autonomous navigation project, both past and present, at the Center for Intelligent Machines and Robotics. Individual thanks go to the project manager, David Armstrong, for his invaluable input, and to office mate David Novick, for his unending programming advice. Finally, special thanks go to the author’s wife, Jennifer Lisa Wit, who provided continuous encouragement and inspiration needed to finish this dissertation. ii
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